标题： 南扎纳杜和图伊地区水冰特征的分布和强度 显示英文标题

标题： Distribution and intensity of water ice signature in south Xanadu and Tui Regio

摘要： 土卫六的表面由卡西尼号的仪器揭示，显示出湖泊中存在液态碳氢化合物，以及干涸河床等特征。 为了研究土卫六渠道中的沉积物搬运，并绘制这些地形中水冰特征的分布，我们使用辐射传输模型来反演地表反照率，在此之前我们通过一种原创方法估计了VIMS的误差。 我们还建立了一个与水冰特征强度相关的标准。 辐射传输模型的调校表明，土卫六气溶胶的分形维数高于之前的估计，约为2.3-2.4。 我们在图伊区域边缘的下游发现了水冰信号增强的斑点，这可能对应于冲积扇、三角洲或陨石坑边缘。 我们还在图伊区域观察到非常低的水冰信号，并且在该区域的中心区域和边界之间存在正梯度，可能是由于蒸发层厚度的变化所致。 河床在误差范围内显示出从渠道顶部到底部颗粒尺寸减小的趋势。 显示英文摘要

摘要： Titan's surface was revealed by Cassini's instruments, showing the presence of liquid hydrocarbons in lakes, and features like dry riverbed. In order to study the sediment transport in Titan's channels and to map distribution of the water-ice signature in these terrains, we use a radiative transfer model to retrieve the surface albedo, after we estimated VIMS error via an original method. We also establish a criteria related to the intensity of the water ice signature. The tuning of the radiative transfer model shows that the fractal dimension of Titan's aerosols is higher than previously thought, around 2.3 - 2.4. We find spots of increasing signal of water ice downstream, at the margins of Tui Regio, that could correspond to alluvial fans, deltas or crater rims. We also observe a very low water ice signal on Tui Regio, with a positive gradient between the central region and the boundary of the area, possibly due to the thickness variation of an evaporitic layer. The riverbeds show within the error bars a decreasing grain size from the top to the bottom of the channels.